I've been using the Makita 9227C for some time now (years) and love it! I tried others, but this one has the best balance in by book!
If you
REALLY need one, I would take the time to tape your edges as paint is a bit thinner in those areas and once too long there or too fast or hard.... paint gone!
They are used primarily for paint defect removal: Swirls, orange peel, compounding after wetsanding, etc. Swirls can be removed very quickly as a rotary generates heat and can really work a polish into the finish. Speed is the key, too fast and kiss paint goodbye, too slow polishes start to bind up the pads.
If you do have defects as above and want them gone, this is one way to do it. But if it's your first time, please tape all edges. You can hit those later by hand or PC. Take your time, get to know the polisher! Sounds stupid, but balance and feel as you use it is very important! Find a good balance with it, try it sanding wood for a day, then change to a pad and try it on some metal to shine that up. This way you get more confident and find how it reacts with the surface. Keep the pad on a slight angle as well.
Now you have one, tested it, played with it and feel you're ready, then go ahead and polish away. Read polish mfg guide to find best speeds for type of polish. When in doubt, 1000rpm to 1500rpm is a fair speed.
Go to your home centers and pick each one up. If you can, ask if you can find an area to test one running as they do have a lot of torque and you need to feel it as it operates, start stops etc.
The Makita 9227C has a wrap around handle which gives me more control and balance. It can also go from 0-3000.
Here's a good price for one:
Makita 9227C Rotary Polisher
Good luck.
Regards,
Deanski